Q: Mail enciphering in Apple devices.

I use devices of the company and is very happy. I have iPad, iPhone, MacBook.

Now, I want to conduct business correspondence in the ciphered look. But I do not find in Store of convenient programs for this purpose. One programs too expensive stand for simple correspondence, others suggest to use the foreign centers of certification, the third suggest to copy for an encryption interpretation of the letter contents in the program.

Whether there are simple free programs for reading the ciphered correspondence? On the MacBook for mail enciphering I use GPGTools. Is similar for iPhone and iPad?